1. Field of the Invention
The present invention concerns a folded box gluing machine for making folded boxes from blanks, having several processing stations and a conveying mechanism for delivering the blanks through the individual processing stations.
2. Description of the Related Art
Folded boxes are packages of cardboard or corrugated carton, also made from plastic on a small scale, which depending on their design, are glued in one or more places during the folding process. As a rule, the folded boxes are produced from a blank. The blanks are usually punched out on a sheet punch. The blank must be glued on at least one edge. The folded boxes come from the folded box gluing machine in a condition lying flat. The setting up and filling of the boxes can be done by machine or also manually.
Besides the folded seams, which are necessary to make the folded boxes, additional crease lines are also pre-broken (pre-folded) in the folded box gluing machine as preparation for the next production step. In this way, the setting up of the boxes and the later filling is facilitated.
The actual gluing process is only one part of the complex mechanical process in the making of folded boxes. Depending on the kind of box, various folds have to be made in and transverse to the direction of movement of the machine before the glue is applied in order to prepare the folded box for setting up and to apply the glue to the correct place.
Folded box gluing machines for making folded boxes from blanks have several processing stations through which the blanks of the folded boxes move in succession, which are described below.
Feeder
The box blanks are placed between two sideways adjustable stack walls at the feeder. Each time, the lowermost blank is pulled into the machine by revolving feed belts. Thanks to height-adjustable positioning tongues, double feeding can be prevented. As a result, an optimal pulling of the blanks with no marring is assured. The feeder singles out the blanks and ensures a definite distance between the blanks.
Orienting Station
In order to orient the blanks exactly with crease lines parallel to the transport direction for the following folding process, it is known how to arrange a so-called orienting station directly behind the feeder. The orienting of the blanks occurs on a guide strip, which extends in the transport direction, and the blanks are moved sideways against it.
Pre-Breaker
In the pre-breaker, the crease lines are pre-broken and then passed on, lying flat again, to the following station. Thanks to the pre-breaking (folding back and forth) of the crease lines, they are made soft and flexible. In this way, glued boxes can be opened more easily, and their filling is simplified. The pre-breaker also makes it possible to add on accessories.
Folding Station
Here, the blanks are folded and glued. The bottom gluing unit at the start of the station enables a precise glue application and low-spray operation, even at the highest production speeds.
Transfer Station
The glued boxes are prepared in the station for peeling off and transfer to the pressing station. When code readers or glue application checking are used, defective boxes can be taken out of line at the transfer station by an accessory device. At this station, the boxes are counted, and individual boxes are set down with a sideways offset by a marking device. In this way, the stream of boxes is optimally prepared for a fast and easy manual pick-up.
Collecting and Pressing Unit
In the slower-running pressing station, the peeled-off boxes are taken, under precisely adjustable pressure, between revolving press belts, to give the glue time to set even at high production speeds. For this, folded box gluing machines can be outfitted with an electronic mechanism to control the speed for the collecting and pressing unit, depending on the blanks. This automatically ensures the precise peeling rate and thus a uniform pressing of the boxes even when the stream of boxes is changing.
Accessory Machines
The option exists of installing semiautomatic or fully automatic packing machines after the collecting and pressing unit. The glued boxes are then packed by machine directly into larger boxes and made ready for an easier handling. In addition, at the feeder of a folded box gluing machine there can also be connected a pre-feeder for supplying an uninterrupted stream of folded box blanks.
With the option of a pre-feeder and a packing machine at the folded box gluing machine, a comprehensive fully automatic system is provided for highest production performance and product quality so as to provide a highly economical system, exactly tailored to the needs of the professional user. Furthermore, glue application and checking devices, glue nozzle units (for cold and hot glue), and code readers and glue application checkers can be integrated.
The transport of the blanks through the individual processing stations occurs by upper and lower conveying belts, which are each supported at their side a location spaced away from the blanks. As a rule, two pairs of narrow belts are used across the width of the machine, and they can be positioned crosswise to adjust to different box formats for an optimal line of contact with the blanks. Position displays for adjusting the roller bars to the format enables brief setup times for adjustments and repeat production runs. The upper roller bars can be lifted. This simplifies the adjustment work and reduces setup time. Furthermore, the blanks can easily be taken out.
Such folded box gluing machines are known, for example, from EP 10 01 877 B1.
If the folded boxes are used to pack pharmaceuticals, it is mandated by law to affix (e.g., by embossing) the name of the drug in script for the blind (so-called Braille script) on the folded box. For this, a technical guideline “Script for the blind in the production of folded boxes” has been issued by the Folded Box Industrial Association to serve as a guide for the standardized production of script for the blind on folded boxes.
As is known, the embossing of the script for the blind occurs during the punching process at the sheet punch when the blanks are produced. But this is costly, since a punched sheet contains quite a few copies (blanks) and each copy needs a pair of dies consisting of male and female dies. Thus, very high tooling costs arise. Furthermore, it has been found that the punched sheets have a tendency to get stuck on the embossing dies for the Braille script and thus impair the punching process. Moreover, it is difficult to emboss the crease lines and the Braille script at the same time, if the Braille script is located near the crease lines. The dies for the embossing of the crease lines and the Braille script need to have a minimum spacing from each other. What is more, the necessary adjustment time is increased because of the many dies in the punching form.